A. Field of the Invention
This invention is a molded plastic basket and rear panel for a shopping cart, in particular a basket for a nestable shopping cart including a wheeled chassis.
B. Related Art
Molded plastic baskets and rear panels for shopping carts have been described in the patent literature, for example U.S. Pat. No. 5,458,347 granted to Chiv Oct. 17, 1995; U.S. Pat. No. 4,273,346 granted to Rehrig Jun. 16, 1991; U.S. Pat. No. 4,632,411 granted to Badger Dec. 30, 1996; U.S. Pat. No. 3,999,774 granted to Rehrig Dec. 28, 1976 and U.S. Pat. No. 4,650,199 granted to Rehrig Mar. 17, 1987.
Molding of the basket and rear panel portions of plastic shopping carts is typically carried out using injection or compression molding techniques using outer moveable mold sections that cooperate with an inner core to mold the entire basket and, if desired, rear panel in a one shot molding process. When the basket is formed of a gridwork of narrow yet relatively tall ribs, it will be appreciated that molding problems may be encountered if the ribs run other than perpendicular to the upright and longitudinal directions of the basket, and if the basket has curved corner sections. If the ribs run at an angle, for example, of 45.degree., the front corner portions of the basket need to be configured so that the vertically moveable molds used to form the side and front walls of the basket can be removed after the molding operation to release the molded gridwork.
Due to molding requirements, the front corner portions of plastic baskets for shopping carts are typically molded in substantially square configuration or with a special grid formation that ensures moldability at the corner sections. In particular, the corner sections of the basket must be configured such that the molds forming the sides of the basket can move away from the sides after molding and the mold forming the front of the basket also can move away from the front molded section as well. In a conventional molding system, the side and front mold sections move approximately at right angles relative to each other.
If it is desired to form the front corners of the molded plastic basket with an arcuate convex configuration while preserving the appearance of a 45.degree. gridwork as it traverses the rounded portion, the molding problem becomes acute as the mold parting line is approached in the front corner areas of the basket. Conventionally, the mold parting line is located at the front corner zones of the basket where the mold side sections join the front mold section when the mold is fully closed. It has been discovered that an attempt to simply contour the gridwork ribs around the arcuate front corner sections of the basket results in a widening of the inner edges of the ribs forming the gridwork of the front and side walls of the basket as the parting line of the mold is approached. Accordingly, the present invention addresses the problem of providing an attractive, unique appearance for a plastic shopping cart basket having a non-upright gridwork of ribs forming the basket side and front walls, namely rounded front corner profiles, while maintaining a uniform appearing gridwork of the ribs as the ribs traverse the rounded front corner sections of the basket adjacent the mold parting line.